/*
 * Copyright (c) 2004-2022, University of Oslo
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors 
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.hisp.dhis.dataelement;

import static org.hisp.dhis.category.CategoryCombo.DEFAULT_CATEGORY_COMBO_NAME;

import java.util.Iterator;
import java.util.Map;
import lombok.RequiredArgsConstructor;
import org.hisp.dhis.category.CategoryCombo;
import org.hisp.dhis.category.CategoryService;
import org.hisp.dhis.dataset.DataSet;
import org.hisp.dhis.dataset.DataSetElement;
import org.hisp.dhis.legend.LegendSet;
import org.hisp.dhis.option.OptionSet;
import org.hisp.dhis.system.deletion.DeletionVeto;
import org.hisp.dhis.system.deletion.IdObjectDeletionHandler;
import org.springframework.stereotype.Component;

/**
 * @author Lars Helge Overland
 */
@Component
@RequiredArgsConstructor
public class DataElementDeletionHandler extends IdObjectDeletionHandler<DataElement> {
  private final CategoryService categoryService;

  @Override
  protected void registerHandler() {
    whenDeleting(CategoryCombo.class, this::deleteCategoryCombo);
    whenDeleting(DataSet.class, this::deleteDataSet);
    whenDeleting(DataElementGroup.class, this::deleteDataElementGroup);
    whenDeleting(LegendSet.class, this::deleteLegendSet);
    whenVetoing(OptionSet.class, this::allowDeleteOptionSet);
  }

  private void deleteCategoryCombo(CategoryCombo categoryCombo) {
    CategoryCombo defaultCategoryCombo =
        categoryService.getCategoryComboByName(DEFAULT_CATEGORY_COMBO_NAME);

    for (DataElement dataElement : idObjectManager.getAllNoAcl(DataElement.class)) {
      if (dataElement != null && dataElement.getCategoryCombo().equals(categoryCombo)) {
        dataElement.setCategoryCombo(defaultCategoryCombo);

        idObjectManager.updateNoAcl(dataElement);
      }
    }
  }

  private void deleteDataSet(DataSet dataSet) {
    Iterator<DataSetElement> elements = dataSet.getDataSetElements().iterator();

    while (elements.hasNext()) {
      DataSetElement element = elements.next();
      elements.remove();

      dataSet.removeDataSetElement(element);
      idObjectManager.updateNoAcl(element.getDataElement());
    }
  }

  private void deleteDataElementGroup(DataElementGroup group) {
    for (DataElement element : group.getMembers()) {
      element.getGroups().remove(group);
      idObjectManager.updateNoAcl(element);
    }
  }

  private void deleteLegendSet(LegendSet legendSet) {
    for (DataElement element : idObjectManager.getAllNoAcl(DataElement.class)) {
      for (LegendSet ls : element.getLegendSets()) {
        if (legendSet.equals(ls)) {
          element.getLegendSets().remove(ls);
          idObjectManager.updateNoAcl(element);
        }
      }
    }
  }

  private DeletionVeto allowDeleteOptionSet(OptionSet optionSet) {
    String sql = "select 1 from dataelement where optionsetid = :id limit 1";
    return vetoIfExists(VETO, sql, Map.of("id", optionSet.getId()));
  }
}
